Work clamp



^ June 13, 1944.

vWQRK LAMP Filed Jan. 9, 1945' l Y Wl Inl' III

INVENTOR. YCaf/e.: 7T Kez yc. T. KETz 2,351,436

Patented June 13, 1944 UNITED STATES PATENT OFFICE 2,351,436 WORK CLAMP Charles T. Ketz, Novelty, Ohio Application January 9, 1943, Serial No. 471,909

6 Claims.

This invention relates to meansl for clamping Work to the tables of machine tools, such as drill presses, Shapers and the like, and it consists of an improved support or so-called packing block for use in such means.

In addition to the packing block, clamping means of the aforesaid class include a clamp bar or strap which bears at one end upon the block, and at the other on the piece of work that is to be secured to the machine table; a bolt that has its head suitably interlocked with the table and extends vertically through a hole in the strap, and a nut that is threaded on the bolt for engagement with the top side of the strap and is adapted to be drawn down tightly to clamp the parts securely to the machine table.

Among the objects of the invention are to provide a packing block incorporating a plurality of ledges, each having a clamp seat, and with any one of which the end of the strap may be engaged, thereby adapting the clamping means, whereof the block forms a part, to pieces of work of different thicknesses; to provide a packing block wherein all seats are relatively close to the vertical axis of the block so as to render the block compact and well balanced, and permit the use of a comparatively short strap, enhancing rigidity and effectiveness of the clamping means; and to provide a device of the aforesaid character that is very simple of construction and relatively inexpensive; that is safe in that it is free from projections on which clothing or other objects may catch; that is so designed as to enable it to be cast and yet be very strong, and

that stands rmlyupon the machine table without liability of tilting when under extreme pressure.

The foregoing objects, with other and more limited ones hereinafter appearing, are attained in the embodiment of the invention illustrated in the accompanying drawing wherein Fig. 1 is an elevational View showing a part of a machine tool table to which is secured a piece of work by clamping means involving my improved packing block; Fig. 2 is a plan View of the packing block, and Fig. 3 is a side elevational view thereof taken from a position to the left of Fig. l.

According to the present preferred embodiment of the invention, the block is cast of suitable metal and comprises a body portion I that is square in cross section and rises centrally from a broad flat base 2 that is adapted to rest upon the table 3 of a machine tool.

For convenience in describing the invention, it Will be assumed that the block is in the posi- UJI tion it occupies when in use-that is,.with the base 2 horizontal. Extending from each of the Vertical faces of the body portion I are a series of ledges 5. Each ledge has a flat horizontal clamp seat 5a, and one end of a clamp bar or strap 6 is adapted to be engaged with the seat 5a of any one of the ledges, while the opposite end thereof bears upon a part of the piece of work 'I that is to be clamped to the table 3. A bolt I0 has its square, or other suitably shaped head I I engaged .within a T-slot I2 of the table 3 so as to securely anchor the bolt to the table and prevent its turning with respect thereto while permitting convenient adjustment of the bolt along the slot. The bolt extends through a hole in the strap 6 and has applied to it a nut I4 by which the strap may be forced toward the table to rmly clamp the work 'I and, incidentally, the packing block thereto.

The arrangement of the ledges 5 may best be described by saying that they are disposed in a sort of spiral about the body portion as they progress axially thereof in somewhat the nature of a helix or thread of a screw, with the distance between adjacent seats 5a on each face of the body portion corresponding to the pitch of the screw. The planes of the clamp seats of the successive ledges are desirably spaced equal distances apart along the axis of the block and are normal thereto, and the ledges on each side of the body portion are in a common vertical plane parallel to said side. This requires all ledges above the bottom ones to be undercut so as to provide ample room for the end of the clamp bar or strap, While, by reason of the spiral arrangement, the planes of the successive steps are relative close together, thereby adapting a single block to pieces of Work Whose clamp engaging surfaces are quite varied in their spacing from the plane of the machine table. This arrangement also contributes to the compactness of the block and permits use of a comparatively short clamp strap, both of which are factors in the attainment of rigidity and efficiency of the clamping means.

So as to reduce the weight of the packing block and conserve material from which it is constructed, the body portion may be made hollow, as by having an opening I5 extending axially therethrough.

Having thus described my invention, what I claim is:

1. A packing block for use in clamping means of the class described comprising a body portion having a base and a side at substantially right angles to the plane of the base, and a plurality of ledges projecting from said side and spaced apart axially of the body portion, those above the bottom one being undercut and each being provided with a flat clamp seat that is normal to the axis of the body portion.

2. A packing block for use in clamping means of the class described comprising a base, a body portion projecting at substantially right angles therefrom and Yhaving across sectional area less than the area of the base, and a series of ledges extending from a side of the body portion and being disposed one above another in Vertical alignment, those above the bottom one being undercut, the ledges having clamp seats substantially parallel to the base, the base projecting beyond the side of the body portion from which said ledges extend.

3. A packing block for use in clamping means o the class described comprising a base, a body portion extending at substantially right angles therefrom and from a pluralityof sides of which extend ledges having clamp seats that are in planesparallel to that 'of bearing surfaoe of the base, the ledges on the respective 'sidesoi the body portion being disposed one above another in vertical alignment and the ones above the bottom ledge being undercut.

4. A packing block for use in clamping means of the class descrbedcomprising a base, a body portion extending -at substantially right angles therefrom, and flat surfaced clamp lseats .projecting from the sides of the body portion and Whose clamp engaging surfaces are normal to the axis of the body portion, said seats being disposed spirally about the body portion so that they are spaced apart axially thereof, all seats except the lowermost having the form of an undercut ledge.

5. A packing block for use in clamping means of the class described comprising a relatively flat Wide base, a body portion that is rectangular in cross section rising substantially centrally therefrom, and a series of ledges extending from each face of the body portion and disposed one above another in vertical alignment, the ones above the bottom ledge of each series being undercut, the ledges of the various faces being disposed spirally about the body portion as they progress axially thereof, each ledge having a flat horizontal clamp seat.

6. A packing block for use in clamping means of the class described comprising a relatively flat Wide base, a body portion that is Square in cross section rising substantially centrally therefrom, and a series of ledges extending from each face of the body portion and disposed one above another in vertical alignment, the ones above the bottom ledge of each series being undercut, the ledges of the various faces being disposed spirally about the Vbody portion as they progress axially thereof, each ledgehaving 'a flat horizontal clamp seat, and the body portion being provided with an axial opening.

CHARLES T. KE'TZ. 

